Dyeable fiber-forming mixtures of acrylonitrile polymers and alkenyl haloacetate polymers



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DYEABLE FIBER-FGRMING MIXTURES F ACRYLONITRlLE POLYNIERS AND ALKE- NYLHALOACETATE POLYMERS Alfred B. Craig and George E. Ham, Decatur, Ala.,as-

signors to The Chemstrand Corporation, Decatur, Ala, a corporation ofDelaware No Drawing. Application March 2, 1953, Serial No. 339,911

20 Claims. (Cl. 260-455) This invention relates to polymericcompositions having unusual fiber-forming properties. More specifically,the invention relates to polymeric acrylonitrile compositions capable ofbeing converted readily into dyeable general purpose fibers.

This application is a continuation-in-part of our copending applicationSerial No. 208,088, filed January 26, 1951, now U. S. Patent No.2,719,834.

It is well-known that polyacrylonitrile, and various copolymers ofacrylonitrile and other olefinic monomers, can be spun into syntheticfibers having unusual physical properties. Because polyacrylonitrile andthe many 00- polymers of acrylonitrile are almost inert chemically,conventional dyeing procedures are not useful in processing them. Manycopolymers of acrylonitrile have been prepared using as the comonomersubstances which impart dye afiinity. Copolymers of this type are notalways satisfactory because of the excessive cost of the dye-receptivecomonomers and because the introduction of such substances oftendepreciates the desirable fiberforming characteristics of the copolymer.

The primary purpose of this invention is to provide a new acrylonitilepolymer composition which has the chemical and physical properties ofpolyacrylonitrile, and which can be made completely dye-receptive bysimple readily practicable procedures. A further purpose of thisinvention is to provide a means for converting non-dyeable acrylonitrilepolymers into a dye-receptive form. A still further purpose is toprovide new general purpose synthetic fibers.

In accordance with this invention it has been found thatpolyacrylonitrile and other non-dyeable polymers of acrylonitrile, forexample the polymers of over 80 percent acrylonitrile and up to 20percent of other olefinic monomers, such as vinyl acetate, styrene,alpha-methylstyrene, methacrylonitrile, vinyl chloride, vinylidenechloride, and the various alkyl acrylates, alkyl methacrylates, alkylfumarates, and alkyl maleates wherein the alkyl groups have up to fourcarbon atoms may be readily converted into dyeable polymers. This isachieved by blending the non-dyeable polymers with polymericcompositions derived by the polymerization of unsaturated esters ofhaloacetic acid which polymeric compositions have been previouslytreated or are thereafter treated in the blended form withmercapto-substituted heterocyclic nitrogen compounds. Suitable monomersfor polymerization into the useful polymeric compositions are thoserepresented by the generic formula:

wherein X is a halogen atom and R is a radical selected from the groupconsisting of vinyl, allyl, methallyl and isopropenyl. Suitablemonomeric substances include vinyl chloroacetate, allyl chloroacetate,methallyl chloro acetate, isopropenyl chloroacetate, and thecorresponding bromine analogues.

The proportions of the unsaturated halogen containing 2,752,324 PatentedJune 26, 1956 polymer will depend upon the degree of dye-receptivitydesired, and upon the proportion of the alkenyl chloroacetate in theblending polymer. In general, it is desirable to have from two to 20percent of the fiber-forming composition in the polymeric form of thealkenyl chloroacetate. Thus, if the blending polymer is percent alkenylchloroacetate polymer, from two to 20 percent will be required todevelop suitable dye-receptivity. If a copolymer of the chloroacetateand another monomer is used, proportionately more will be required toobtain the desired end result. Polymers of more than 30 percent of thehaloacetate monomers and up to 70 percent of another olefinic monomermay be employed. These other monomers may be acrylonitrile,methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride,styrene, alpha-methylstyrene, and the various alkyl acrylates, alkylmethacrylates, alkyl tumarates, and the alkyl maleates, wherein thealkyl radicals have up to four carbon atoms. Because polymers ofacrylonitrile have unusual solvent and chemical resistance the preferredblending polymer is one of substantial portions of acrylonitrile andsuflicient of the chloroacetate monomer to develop dye-receptivity inthe portions to be blended with the fiber-forming acrylonitrile and 50percent of the alkenyl chloroacetate, for example methallylchloroacetate.

The base polymers are preferably prepared in an aqueous medium in thepresence of a water-soluble peroxy catalyst and in the presence of anagent which maintains the polymer in a fine but granular dispersedcondition. Suitable peroxy catalysts are the alkali metal persulfatesand suitable dispersing agents are the alkali metal salts of sulfonatedhydrocarbons. Polymerization may be conducted by batch procedures, bycontinuous procedure or by combinations of these procedures. A preferredmethod of preparation involves a batch procedure wherein the desiredmonomers are mixed and charged gradually throughout the polymerization.Un usually uniform polymers may be obtained by also charging thecatalyst and emulsifier continuously or in increments throughout thecourse of the reaction. More uniform polymerization conditions may beachieved by operating at uniform temperatures, for example the refluxtemperature of the medium, especially if the operation is so conductedas to provide a constant temperature at reflux.

If desired, the polymerization reaction may be conducted in the presenceof a redox agent, for example, sulfur dioxide, sodium bisulfite, sodiumthiosulfate, or other sulfur compounds in which the sulfur is present inan oxidizable condition. Other optional procedures may involve the useof regulators which serve as chain terminators to prevent the formationof very high molecular weight increments, agents of this type beingt-dodecyl mercaptan, thioglycolic acid, and dithioglycidol.

The procedure for preparing blending polymer is substantially the sameas that used in the preparation of the base polymer. However, theblending polymer may be prepared by other known polymerization methodssuch as mass polymerization or suspension polymerization.

in order to convert the fiber-forming blends containing an increment ofthe chloroacetate polymers into readily dyeable forms, it is necessaryto react the chloroacetate group with a compound which will introduce anamino nitrogen atom. Suitable reagents of this type are the mercaptosubstituted heterocyclic nitrogen compounds and the alkali metal saltsthereof.

In this manner a nitrogen atom. is introduced into the molecule whichwill provide a nucleous for chemical reaction with conventional aciddyestuffs. Suitable compounds of this type for use in the development ofdyereceptivity are mercaptobenzothiazole, 2-mercaptopy- Iidine, 3mercapto 1,2,4-triazole, 2-mercapto-4,5-benzo- 3 1,3 triazine, 2mercaptobenzothiazine, 2 mercapto 4- phenylthiazole,3-mercapto-5phenyl-1,2,4-triazine, 2- mercaptobenzoxazole, l phenyl 3mercapto 1,2,4-triazolone-S, and other mercapto substitutedcompoundscontaining nitrogen hetero rings and the mercapto groups substituted ona carbon atom of the ring, as well as the alkali metal salts of any ofthese compounds.

The polymer may be treated with the mercapto substituted heterocyclicnitrogen compounds in granular solid state, in solution in a suitablesolvent, and in the form of .a. spun fiber. If the polymer is in solidform, obviously only the surface will be reacted chemically, and if thepolymer is treated in solid form before spinning the activated surfacemay be substantially diluted when the polymer is dissolved and reformedinto fibers. Accordiingly, the most effective procedure involveschemical treatment in solution state.

This modification may take place in the spinning solution from which thefibers will ultimately be prepared. Accordingly, the polymers are'polymer solution can then be blended with a solution of the basepolymer in the same, or compatible, solvents.

In the practice of this invention the dyeable fiberforming compositionsare prepared by mixing the solid polymers in suitable conventionalmechanical mixers, for example, Banbury mixers, roll mills, or doughmixers. In general, it is desirable to add the solvents or plasticizersfor fiber-forming acrylonitrile polymers. The intimate mixing of thepolymers or blended polymers with the reagent may induce the reaction ofsubstantially all of the chloroacetate groups. Less thorough mixing, andespecially if the polymer solutions are quite viscous will induce thereaction of only a small proportion, for example from five to 50 percentof the chloroacetate groups with the reactant. Under such conditions itwill be necessary to add more of the chloroacetate polymers in order todevelop the desirable extent of dye-receptivity. Thus, the manner ofmixing and the viscosity of the blending mixture must be considered inselecting the proper proportions of polymers.

The new blended compositions may be fabricated into synthetic fibers byconventional wet or dry spinning pro cedures. After stretching thefibers to develop the nec- 'cssary orientation and the incident tensilestrength, and

thereafter shrinking the fibers to improve their thermal resistance,valuable general purpose fibers are obtained.

Further details of this invention are set forth with respect to thefollowing examples:

Example I A skcin of fibers (0.6 gram) composed of a blend of acopolymer of 97 percent acrylonitrile-3 percent vinyl acetate and acopolyrner of 60.5 percent acrylonitrile- 395 percent methallylchloroacetate, with an overall methallyl chloroacetate content of 8percent was immersed for five minutes at 100 C. in a mixture consistingof 1.89 grams of mercaptobenzothiazole, 0.45 gram of sodium hydroxideand 60 mls. of Water. The fiber was then washed and dried. The fiber wasthen dyed in a dye bath containing 0.6 ml. of 2 percent Wool FastScarlet, 3.0 mls. of five percent sulfuric acid, and 24 mls. ofdistilled water for one hour at 100 C. A deep scarlet fiber wasproduced. A similar fiber which was not treated withmercaptobenzothiazole was dyed a very light shade.

Example II The procedure of Example I was duplicated, except percentvinyl chloroacetate was blended with a copolymer of 97 percentacrylonitrile-3 percent vinyl acetate to give an overall vinylchloroacetate content of 8 percent. Fibers produced from thiscomposition were treated with mercaptobenzothiazole as in Example I. Theresulting fibers dyed well with Wool Fast Scarlet, Alizarin Light Blue4GL, and Wool Fast Yellow dyes.

We claim:

1. A method of preparing a dyeable fiber-spinning composition whichcomprises blending (A) a polymer of at least percent by weight ofacrylonitrile and up to 20 percent of another mono-olefinic monomercopolymerizable therewith, and (B) a polymer of at least 30 percent byweight of an alkenyl haloacetate of the structure:

wherein X is a halogen atom selected from the group consisting ofchlorine and bromine and R is a radical selected from the groupconsisting of vinyl, allyl, methallyl and isopropenyl, and up to 70percent of another monoolefinic monomer copolymerizable therewith, theonly source of alkenyl haloacctate in the blend being the (B) polymer,the polymers being blended in such proportions that from 2 to 20 percentof the total Weight is the said alkenyl haloacetate, and reacting theblended polymer with a compound of the group consisting of mercaptosubstituted N-heterocyclic compounds, wherein the mercapto group issubstituted on a carbon atom, and alkali metal salts thereof.

2. A dyeable fiber-spinning composition comprising a blend of (A) apolymer of at least 89 percent by weight of acrylonitrile and up to 20percent of another monoolefinic monomer copolymerizable therewith and(B) a polymer of at least 30 percent by weight of an alkenyl haloacetateof the structure:

wherein X is a halogen atom selected from the group consisting ofchlorine and bromine and R is a radical selected from the groupconsisting of vinyl, allyl, methallyl and isopropenyl, and up to 70percent of another monoolefinic monomer copolymerizable therewith, andwherein the only source of the alkenyl haloacetate in the blend is the(B) polymer, the polymers being blended in such proportions that from 2to 20 percent of the total weight is the said allrenyl haloacetate, thesaid blend having been reacted with a compound of the group consistingof mercapto substituted N-heterocyclic compounds, wherein the mercaptogroup is substituted on a carbon atom, and alkali metal salts thereof.

3. A method of preparing a dyeable fiber-spinning composition Whichcomprises reacting (A) a polymer of at least 30 percent by weight of analkenyl haloacetate of the structure:

wherein X is a halogen atom selected from the group consisting ofchlorine and bromine and R is a radical selected from the groupconsisting of vinyl, allyl, methallyl and isopropenyl, and up to 70percent of another mono-olefinic monomer copolymerizable therewith, witha compound of the group consisting of mercapto substitutedN-heterocyclic compounds wherein the mercapto group is substituted on acarbon atom, and alkali metal salts thereof, and blending the so reactedpolymer with (B) a polymer of at least 80 percent by weight ofacrylonitrile and up to 20 percent of another monoolefinic monomercopolymerizable therewith, said polymer (A) being the only source ofalkenyl haloacetate in the blend and the polymers being blended in suchproportions that from 2 to 20 percent of the total weight is the saidalkenyl haloacetate.

4. A dyeable fiber-spinning composition comprising a blend of (A) apolymer of at. least 80 percent by weight of acrylonitrile and up to 20percent of another monoolefinic monomer copolymerizable therewith and(B) a polymer of at least 30 percent by weight of an alkenyl haloacetatehaving the structure:

wherein X is a halogen atom selected from the group consisting ofchlorine and bromine and R is a radical selected from the groupconsisting of vinyl, allyl, methallyl and isopropenyl, and up to 70percent of another mono-olefinic monomer copolymerizable therewith thepolymers being blended in such proportions that from 2 to 20 percent ofthe total weight is the said alkenyl haloacetate, said haloacetate inpolymeric form having been reacted with a compound selected from thegroup consisting of mercapto substituted N-heterocyclic compoundswherein the mercapto group is attached to a carbon atom, and alkalimetal salts of such compounds, and polymer (B) being the only source ofalkenyl haloacetate in the blend.

5. A dyeable fiber-spinning composition comprising a blend of (A) apolymer of at least 80 percent by weight of acrylonitrile and up to 20percent of another monoolefinic monomer copolymerizable therewithselected from the group consisting of vinyl acetate, vinyl chloride,vinylidene chloride, methacrylonitrile, styrene, dialkyl fumarates,dialkyl maleates, alkyl acrylates and alkyl methacrylates wherein thealkyl groups have up to four carbon atoms, and (B) a polymer of at least30 percent by weight of an alkenyl haloacetate of the structure:

wherein X is a halogen atom selected from the group consisting ofchlorine and bromine and R is a radical selected from the groupconsisting of vinyl, allyl, methallyl and isopropenyl, and up to 70percent of another mono-olefinic monomer copolymerizable therewithselected from the group consisting of vinyl acetate, vinyl chloride,vinylidene chloride, acrylonitrile, methacrylonitrile, styrene, dialkylmaleates, alkyl, acrylates and alkyl methacrylates, wherein the alkylgroups have up to four carbon atoms the polymers being blended in suchproportions that from 2 to 20 percent of the total weight is the saidalkenyl haloacetate, the said blend having been reacted with a compoundselected from the group consisting of mercapto susbtitutedN-heterocyclic compounds wherein the mercapto group is attached to acarbon atom, and alkali metal salts of said compounds.

6. A dyeable fiber-spinning composition comprising a blend of (A) a polyer of at least 80 percent by weight of acrylonitrile and up to 20percent of another monoolefinic monomer copolymerizable therewithselected from the group consisting of vinyl acetate, vinyl chloride,vinylidene chloride, methacrylonitrile, styrene, dialkyl fumarates,dialkyl maleates, alkyl acrylates and alkyl methacrylates wherein thealkyl groups have up to four carbon atoms, and (B) a polymer of at least30 percent by weight of an alkenyl haloacetate of the structure:

wherein X is a halogen atom selected from the group consisting ofchlorine and bromine and R is a radical selected from the groupconsisting of vinyl, allyl, methallyl and isopropenyl, and up to percentof another monoolefinic monomer copolymerizable therewith selected fromthe group consisting of vinyl acetate, vinyl chloride, vinylidenechloride, acrylonitrile, methacrylonitrile, styrene, alkyl fumarates,alkyl maleates, alkyl acrylates and alkyl methacrylates, wherein thealkyl groups have up to four carbon atoms, the polymers being blended insuch proportions that from 2 to 20 percent of the total weight is thesaid alkenyl haloacetate, the said haloactate in polymeric form havingbeen reacted with a compound of the group consisting of mercaptosubstituted N-heterocyclic compounds wherein the mercapto group isattached to a carbon atom, and alkali metal salts of said compounds.

7. A dyeable composition as defined in claim 2 wherein the haloacetateis vinyl chloroacetate.

8. A dyeable composition as defined in claim 2 wherein the haloacetateis allyl chloroacetate.

9. A dyeable composition as defined in claim 2 wherein the haloacetateis methallyl chloroacetate.

10. A dyeable composition as defined in claim 2 where in the haloacetateis isopropenyl chloroacetate.

11. A dyeable composition as defined in claim 4 wherein the haloacetateis vinyl chloroacetate.

12. A dyeable composition as defined in claim 4 wherein the haloacetateis allyl chloroacetate.

13. A dyeable composition as defined in claim 4 wherein the haloacetateis methallyl chloroacetate.

14. A dyeable composition as defined in claim 4 wherein the haloacetateis isopropenyl chloroacetate.

15. A dyeable composition as defined in claim 2 wherein the compound ismercaptobenzothiazole.

16. A dyeable composition as dfined in claim 2 wherein the compound isan alkali metal salt of mercaptobenzothiazole.

17. A dyeable composition as defined in claim 2 where in the compound isthe sodium salt of mercaptobenzothiazole.

18. A dyeable composition as defined in claim 4 wherein the compound ismercaptobenzothiazole.

19. A dyeable composition as defined in claim 4 wherein the compound isan alkali metal salt of mercaptobenzothiazole.

20. A dyeable composition as defined in claim 4 wherein the compound isthe sodium salt of mereaptobenzothiazole.

Gluesenkamp et al. June 30, 1953 Chaney et a1. Aug. 31, 1954

1. A METHOD OF PREPARING A DYEABLE FIBER-SPINNING COMPOSITION WHICHCOMPRISES BLENDING (A) A POLYMER OF AT LEAST 80 PERCENT BY WEIGHT OFACRYLONITRILE AND UP TO 20 PERCENT OF ANOTHER MONO-OLEFINIC MONOMERCOPOLYMERIZABLE THEREWITH, AND (B) A POLYMER OF AT LEAST 30 PERCENT BYWEIGHT OF AN ALKENYL HALOACETATE OF THE STRUCTURE: